AANA Journal course: update for nurse anesthetists--genetic testing for malignant hyperthermia

The "gold standard" for the determination of susceptibility to malignant hyperthermia has long been the caffeine-halothane-contracture test, which is costly and invasive. As the workings of molecular genetics are better understood, research is being applied to finding the causative gene for malignant hyperthermia. Once this gene is identified, genetic testing will involve a much simpler, less invasive test that uses blood samples to detect susceptibility. To reach this goal, researchers have been attempting to identify the deoxyribonucleic acid (DNA) mutations responsible for malignant hyperthermia by using techniques such as linkage analysis. Review of the literature reveals that malignant hyperthermia has been linked to the ryanodine receptor in swine and in some humans. It has also been linked to chromosome 19q12-13.1, which is where the gene encoding the ryanodine receptor lies. The literature further reveals that malignant hyperthermia may be a heterogeneous disorder, which means that more than one gene is responsible for its expression.